whats up fellas, im enjoying my new cummins bigtime, its like im a kid again with all this torque.anyway heres my question, i noticed when im street racing off the line and through first and second truck pulls great, and even when it shifts into third, but when it hits around 2900 or3000 rpms it really stops pullin until it shifts into fourth, then pulls hard again. its an auto 4 speed 48re. somebody shed some knowledge my way, thanks guys george

 

If I am gauging what you are saying correctly, that is normal... the "pulls hard again" you describe sounds like when the TC locking up in 4th. Install and use a TC lock up switch and get that "pull" from 2nd gear on... although be warned that is hard on the shafts.

 

Yeah, mine does the same thing. If you watch the shift points in the attitude, you will see that it is when the tc locks up that you get your power back. I think that those with beefed up tranny's get this power all the way through the rpm range.